Camarasa, M. and Barnils, C. and Puig De La Bellacasa, R. and Teixidó, J. and Borrell, J.I., A new and practical method for the synthesis of 6-aryl-5,6-dihydropyrido[2, 3-d]pyrimidine-4,7(3H,8H)-diones, Molecular Diversity, 2013, 17, 525-536.